198 CLAVicoRNiA. [Hislerida. 



1. Anteuiifc insn'ted iu cavities which are anterior, 



open iu front, and more or less completely closed 

 beneath by the lobe of the prosternum, which is 

 strong. 



A, Club of antenns3 oval, pubescent, usually dis- 

 tinctly ringed HiSTEB, L. 



B. Club of antennse obconical, without pubescence, 



solid HET.i;Bius, Er. 



2. Autenna? inserted in cavities at the middle of the 



inflexed portion of the thorax, uear the sides. 



A. Middle and posterior tibiae slender ; front tibise 



dilated. 



a. Elytra regularly and strongly striate; body 



oval ; scutelhnn conspicuous ...... Caecinops, Mars. 



b. Elytra with dorsal striae more or less obsolete ; 



body oblong ; scutellum inconspicuous . . . Pakomaltts, Er. 



B. All the tibiae dilated ; body oval Dendeophilfs, Leach. 



ii. Prosternum not lobed in front, truncate. 



1. Antennae inserted under the margin of the fore- 



head ; mandibles pi'ominent. 



A. Anterior tibia3 without distinct spines; upper 



surface very obsoletely striate at sides .... Myemetes, Marsh, 



B. Anterior tibite distinctly spined ; upper surface 



striate and more or less punctured. 



a. Foiehead with a distinct impressed stria . . Sapeintis, Er. 



b. Forehead without impressed stria .... Gnathoncus, Duv. 



2. Antennas inserted on the forehead ; mandibles 



small, not prominent. 



A. Posterior tibiaj distinctly toothed ; form sub- 

 cylindrical Teeeteius, Er. 



B. Posterior tibiae not or scarcely toothed ; form 



more or less ovate. 



a. Tborax with a deep transverse furrow in 



middle PlEGADEETJS, Er. 



b. Thorax without transverse furitiw. 



a*. All the tarsi 5-joiuted ; elytra without 



marginal stria ; size larger Abr^uS, Leach. 



b*. Posterior tarsi 4-jointed ; elytra with mar- 

 ginal stria, situated on epipleurae ; size 



smaller Aceittts, Lee. 



II. Upper surfiice strongly costate ; prosternum feebly 

 lobed in front Onthophiitts, Leach. 



KZSTER, Linne. 



This extensive genus contains at present about three hundred and 

 twenty species, which are widely distributed throughout the world, both 

 in tropical and temperate regions ; about sixty of these species occur iu 

 Europe, fifteen of which are found in Eritain ; two or three of these, 

 however, are doubtfully indigenous ; they are found in dung, hot-beds, 

 decaying fungi, or carcases, and when alarmed, retract their limbs and 

 antennae and remain motionless.* 



* Hence their name, which is the primary Etruscan form of hislrio, an actor, and 

 was applied to them by Liunc iu aihi.siou to their feigning death. 



